Hello,
Thanks for this feedback.
Here the description of the issue I am trying to solve.
I use already tcp_keepalive.
Call flow is: UACs --> Nat device --> Kamailio
Transport protocol is TLS.
Kamailio sends TCPs keepalive (tcp_keepalive option) to the softphone located behind the nat devices in order to prevent disconnection due to network inactivity. In most cases I have the expected behavior, I do not have any problems.
I think somes NAT devices don't properly handle TCPs keepalive because they close the connection after TCP keepalives. I have always this issue with NAT devices using VSS-Monitoring protocol.
A network capture shows: - Kamailio sends a tcp keepalive - The NAT device sends a tck keepalive ACK to Kamailio with a new filed : vss-monitoring Frame 70: 62 bytes on wire (496 bits), 62 bytes captured (496 bits) Linux cooked capture Internet Protocol Version 4, Src: x.x.x.x, Dst: x.x.x.x Transmission Control Protocol, Src Port: 13178, Dst Port: 443, Seq: 2752, Ack: 6214, Len: 0 *VSS-Monitoring ethernet trailer, Source Port: 0* * Src Port: 0*
- Kamailio received then a TCP from the NAT device that notifies the closure of the connection.
Frame 73: 87 bytes on wire (696 bits), 87 bytes captured (696 bits) Linux cooked capture Internet Protocol Version 4, Src: x.x.x.x, Dst: x.x.x.x Transmission Control Protocol, Src Port: 13178, Dst Port: 443, Seq: 3436, Ack: 6214, Len: 31 Secure Sockets Layer TLSv1.2 Record Layer: Alert (Level: Warning, Description: Close Notify) Content Type: Alert (21) Version: TLS 1.2 (0x0303) Length: 26 Alert Message Level: Warning (1) Description: Close Notify (0) - After a FIN ACK sent to Kamailio by the NAT device, a new tcp three-way handshake is made again.
Sometimes, I have this issue during the connection establishment that cause a problem of sending or receiving SIP messages (for examples 200 OK and ACK).
The advantage of the SIP ping options is a bidirectional traffic through NAT. I think in this case, my issue will be solved.
Regards Abdoul OSSENI
2017-04-05 12:48 GMT+02:00 Daniel-Constantin Mierla miconda@gmail.com:
Hello,
nathelper module does ping OPTIONS only for UDP.
For tcp/tls, there is transport layer keepalive:
What is the problem you are trying to solve with this? Maybe there are some other options for it.
Cheers, Daniel
On 31.03.17 13:03, Abdoul Osséni wrote:
Hi,
Is it possible to send ping OPTIONS over tcp or tls?
If yes, could you me how?
Regards Abdoul.
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